Low flow power generation

ABSTRACT

A mobile low-flow water power generation system comprising at least one inlet hose, at least one power generator with an impeller configured for a flow rate of water from the inlet hose designed to generate an electrically compatible output voltage to a load, and an exit hose connected to the generator configured to pass water from the inlet hose without any back pressure.

FIELD OF THE INVENTION

The present invention relates to hydro power generation and more particularly, to a mobile low-flow water power generation system.

BACKGROUND

Renewable energy is becoming more common place than ever before. However, most efforts are being placed into solar and wind power generation. Water power generation can be a viable alternative to extending the grid in geographic areas located adjacent a body of moving water, such as a creek, stream, or river. Water turbines can be used to harness the power of water flow to generate electricity. Deployment of water turbines, however, is typically limited to high-head, high-flow water sites, limiting the suitability of water turbines in many areas.

While high-head, high-flow water sites are relatively scarce, there are many bodies of water throughout the world that can be characterized as providing a low-head, low-flow environment. Low-head, low flow water sources are relatively abundant and can be a good source for providing power in undeveloped areas located off the grid or even in areas where additional energy can be produced and added to the grid.

For centuries, water wheels and stream wheels have been used to harness energy in low-head, low-flow environments. Improvements and developments in water wheel and stream wheel technology have been significantly reduced with the development of the water turbine. There is also an interest in development of micro-hydro and pico-hydro power sources, such as less than 5 kW, for home or community use. However, many of these devices are still large and must have standing structures.

Therefore, there is a need for a mobile low-flow water power generation system.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying figures where:

FIG. 1 is a diagram of a mobile low-flow water power generation system according to one embodiment;

FIG. 2 is a is a diagram of a mobile low-flow water power generation system according to another embodiment;

FIG. 3 is a diagram of a mobile low-flow water power generation system according to another embodiment;

FIG. 4 is a cross-sectional diagram of the system of FIG. 1; and

FIG. 5 is a diagram of decorative version of the system of FIG. 1.

SUMMARY

The present invention overcomes the limitations of the prior art by providing a mobile low-flow water power generation system having at least one inlet hose, at least one power generator connected to the inlet hose and configured to generate an electrically compatible output voltage to a load. The generator has an impeller configured for a flow rate of water from the inlet hose. The system also has an exit hose connected to the generator configured to pass the flow rate of water from the inlet hose without any back pressure being applied to the impeller or generator. A venturi chamber can be added to the inlet hose and coupled to the generator, where the venturi chamber is configured to increase the speed of the water flowing over the impeller. This can increase the speed of the water flow to maximize the amount of electricity that is generated. Conversely, the venturi chamber can be used to restrict the water flow to the generator in case of a spurt of fast moving water, such as, for example, a flash flood, that could cause undesirable spikes in electrical output from the generator.

The system can also have a plurality of inlet hoses of a first size connected by a manifold to at least one inlet hose of a larger, second size coupled to the generator. The manifold can have at least two quick connects for the plurality of inlet hoses and at least one quick connect for the larger, second size inlet hose.

The system can comprise a plurality of single inlet, single outlet low-flow water power generators that are electrically connected to each other in series or in parallel depending on the requirements of an attached electrical load.

The inlet hose has sufficient length to supply a hydraulic head pressure sufficient to have a flow of water over the impeller of at least three feet/second. The inlet hose(s), the venturi chamber, the impeller and the exit hose are configured to maximize electricity produced by the generator for the hydraulic head pressure from the stream. The generator is between two and one hundred pounds to increase the portability of the system. The venturi chamber, inlet and outlet hoses are connectable to the generator inlet by means of a quick connect couplings so that the system can be broken down an easily moved. To prevent ecological damage to wildlife in the stream and to prevent debris from entering the impeller, potentially causing a jam, the inlet hose has a protective front portion. Additionally, the inlet hose has a mounting device to keep the protective front portion of the inlet hose just below the surface of the center of a stream where the maximum water velocity is located, thereby maximizing the hydraulic head pressure. The outlet hose also has a mounting device so that it can be placed in the stream so as to not significantly affect streamflow, stream banks or otherwise cause un-natural erosion of an area around where the generator has been placed.

DETAILED DESCRIPTION

There are over 3.5 million miles of rivers and streams in the U.S. alone, and many more millions of miles worldwide. Small streams, including those that don't flow all of the time, make up the majority of the world's waters. As can be seen in FIG. 6, these water sources, which scientists refer to as headwater streams, are often unnamed and rarely appear on maps. These small streams often appear insignificant, but in fact can be very important as they are often overlooked as a source of power generation.

Typical large power generation plants start by damming a river at a strategic point and creating a huge head water for the turbines at the base of the dam. However, this destroy millions of acres of land by putting it under water. The present invention does not destroy the landscape, and in fact can be merged with the landscape so as not to destroy the natural beauty of the area, while still providing much needed electrical power. By using the present invention in low-head, low-flow environment it is possible to create a significant amount of electrical power that can be grid tied. It has been shown, that a water wheel in a 5-7 mile per hour water flow will produce enough electricity to charge a battery bank. The present invention can use even use water moving slower than that to generate electrical power.

Also, unlike the current hydro-power generation plants that can be affected by water withdrawals for industrial and irrigation purposes, that can seriously deplete water flow, the present invention does not block or remove the water for a long period of time. In fact, dams currently used for electric power generation, particularly facilities designed to produce power during periods of peak need, often block the flow of a stream and later release it in a surge which can damage the downstream environment. The present invention only uses the water temporarily and with sufficient spacing and placement, such that no noticeable effects occur on the surrounding environment.

Because most turbine generators large enough to be connected to a grid will operate at a speed that is predetermined by the grid frequency and the generator's electrical configuration, most notably by increasing the number of poles the generator has, such as, for example, a 60 Hz grid will have generators that operate at either 1800 or 3600 RPM. Typical hydroelectric turbines run much slower and have a large number of poles. Today, there are a great number of low rpm generators that can be grid tied.

Methods and devices that implement the embodiments of the various features of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention. Reference in the specification to “one embodiment” or “an embodiment” is intended to indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an embodiment of the invention. The appearances of the phrase “in one embodiment” or “an embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

Throughout the drawings, reference numbers are re-used to indicate correspondence between referenced elements. In addition, the first digit of each reference number indicates the figure where the element first appears.

As used in this disclosure, except where the context requires otherwise, the term “comprise” and variations of the term, such as “comprising”, “comprises” and “comprised” are not intended to exclude other additives, components, integers or steps.

In the following description, specific details are given to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific detail. Well-known devices, structures and techniques may not be shown in detail in order not to obscure the embodiments. For example, devices may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail.

Also, it is noted that the embodiments may be described as a process that is depicted as a flowchart, a flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process is terminated when its operations are completed. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.

In the following description, certain terminology is used to describe certain features of one or more embodiments of the invention.

The term “streamflow” refers to the flow of water in streams, rivers, and other channels.

The term “static head” refers to the internal energy of a fluid due to the pressure exerted.

The term “hydraulic head” refers to a specific measurement of liquid pressure measured as a liquid surface elevation, expressed in units of length, at the entrance and can be calculated from the depth and elevation by measuring the height of the water surface in a tube relative to a common datum. The hydraulic head can be used to determine a hydraulic gradient between two or more points.

The term “hydraulic gradient” refers to the slope of a line joining the points of highest elevation of water in a series of vertical open pipes rising from a pipeline in which water flows under pressure.

Various embodiments provide a mobile low-flow water power generation system. One embodiment of the present invention provides a system comprising one or more than one low-flow water power generator. In another embodiment, there is provided a method for using the system. The system and method will now be disclosed in detail.

Referring now to FIG. 1, there is shown a diagram 100 of a mobile low-flow water power generation system 100 according to one embodiment. As can be seen, an inlet hose 102 is placed far enough upstream to provide enough static pressure to operate a generator 104. Exit hose 106 provides a path for the water used in power generation to return to the stream without causing any environmental damage.

The inlet hose 102, is sufficiently long enough to divert enough water to create static head pressure great enough to produce the desired electricity from the generator 104. Table 1 below provides a list of calculated static head pressures for a give head pressure value.

TABLE 1 Velocity Head Water (ft/sec) (ft) 0.5 0.004 1.0 0.016 1.5 0035 2.0 0.062 2.5 0.097 3.0 0.140 3.5 0.190 4.0 0.248 4.5 0.314 5.0 0.389 5.5 0.470 6.0 0.560 6.5 0.657 7.0 0.762 7.5 0.875 8.0 0.995 8.5 1.123 9.0 1.259 9.5 1.403 10.0 1.555 11.0 1.881 12.0 2.239 13.0 2.627 14.0 3.047 15.0 3.498 16.0 3.980 17.0 4.493 18.0 5.037 19.0 5.613 20.0 6.219 21.0 6.856 22.0 7.525

Due to the specific weight of water, 62.4 (lb/ft3), it does not take much of a hydraulic gradient for running water to produce a significant force. This force can easily be used to generate quantities of electricity without damaging the environment like larger hydro-electric plants. A static head producing a flow rate of three feet/second is sufficient for a properly configured impeller to turn the generator and produce enough electricity to power a load, such as, for example, charging a battery or powering lights, etc.

The inlet hose(s) should be placed just below the water surface in the center of a stream where the maximum water velocity typically occurs. However, this is not necessary where there are fast moving waters, and safety is a concern. As can be seen from the table above, a small flow rate of water can produce a massive kinetic force that can be converted to electricity.

Referring now to FIG. 2, there is shown a diagram 200 of a mobile low-flow water power generation system 100 according to another embodiment. As can be seen, several inlet hoses 202, 204 and 206 can be joined with a large inlet hose 208 to produce an even larger volume of water that can be used to turn a larger generator 210. Exit hose 106 can be configured to allow the water from the large inlet hose 208 to pass by the large generator 210 with enough speed to produce electricity. The inlet hoses 202, 204 and 206 can be attached to a manifold so that the inlet hoses 202, 204 and 206 can be smaller and less intrusive than a single large inlet hose. A larger inlet hose can be attached to the manifold so that the accumulated static head of water can be sent to the appropriately sized generator/impeller combination to produce electricity. The exit hose 106 must be matched to the static head of water so as not to create a backflow into the impeller that would impede the production of electricity. The inlet hoses 202, 204 and 206 and the outlet hose 106 can be made from any suitable material that will not affect the surrounding environment. Optionally, the inlet hoses 202, 204 and 206 and the outlet hose 106 can be manufactured to blend into the surrounding environment so that the presence of the hoses does not affect the beauty of the surrounding area.

The inlet hoses 202, 204 and 206 can also have a protective front portion that is configured to prevent marine life and debris from entering the inlet hose as is known in the art. A mounting device, such as, for example, a pole or a stake, can be used to keep the protective front portion of the inlet hose just below the surface of the center of a stream where the maximum water velocity is located. The outlet hose also has a mounting device to place the outlet hose in a stream so as to not significantly affect streamflow, stream banks or otherwise cause un-natural erosion of an area around where the system 100 has been placed.

Referring now to FIG. 3, there is shown a diagram 300 of a mobile low-flow water power generation system 100 according to another embodiment. As can be seen, a plurality of mobile low-flow water power generation systems 302, 304, 306 and 308 can be placed in an area proximate to one another so that the systems can be electrically connected in series or parallel, depending upon the power requirements of the attached electrical load.

Referring now to FIG. 4, there is shown a cross-sectional diagram 400 of the system 100 of FIG. 1. As can be seen, the inlet hose 402 can be connected to an optional venturi chamber 404 that is connected to the inlet of the generator 406. The impeller 408 comprises a number of fins that intercept the water flow, thereby turning the generator shaft, producing electricity. The outlet hose 106 is attached to the generator. All of the hose and venturi chamber components are connected to the generator using quick connects that are known in the art. This makes the system 100 more portable and more configurable so that different lengths of inlet hoses 202, 204 and 206 can be used for different streams and streamflows. The outlet hose 106 similarly can be connected to the generator using a quick connect. Additionally, the outlet hose 106 can be larger and different couplings (not shown) can be used to insure that there is no back pressure asserted against the impeller from an impediment in the outlet hose. This also provides additional flexibility to the system 100 because a very large outlet hose 106 can be used with a variety of different sized generators reducing the cost of the system 100 and increasing the portability and mobility of the system 100.

Referring now to FIG. 5, there is shown a diagram 500 of decorative version of the system 100 of FIG. 1. A decorative cover 502 can be placed over the system 100 to protect the system from the elements and blend the system into the surrounding area. The decorative cover 502 can be made from any know material that does not adversely affect the surrounding environment.

What has been described is a new and improved mobile low-flow water power generation system, overcoming the limitations and disadvantages inherent in the related art.

Although the present invention has been described with a degree of particularity, it is understood that the present disclosure has been made by way of example. As various changes could be made in the above description without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be illustrative and not used in a limiting sense. 

What is claimed is:
 1. A mobile low-flow water power generation system comprising: a) at least one inlet hose; b) at least one power generator connected to the inlet hose and configured to generate an electrically compatible output voltage to a load, where the generator has an impeller configured for a flow rate of water from the inlet hose; and c) an exit hose connected to the generator configured to pass the flow rate of water from the inlet hose without any back pressure.
 2. The system of claim 1 further comprising a venturi chamber configured to increase the speed of the water flowing over the impeller.
 3. The system of claim 2, where the venturi chamber is configured to restrict the water flow to the generator to prevent undesirable spikes in electrical output from the generator.
 4. The system of claim 1 further comprising a plurality of inlet hoses of a first size connected by a manifold to at least one inlet hose of a larger, second size coupled to the generator.
 5. The system of claim 4, where the plurality of inlet hoses are connectable to a manifold.
 6. The system of claim 5, where the manifold comprises at least two quick connects for the plurality of inlet hoses and at least one quick connect for the larger, second size inlet hose.
 7. The system of claim 1, where a plurality of single inlet, single outlet low-flow water power generators are electrically connected to each other in series.
 8. The system of claim 1, where a plurality of single inlet, single outlet low-flow water power generators are electrically connected to each other in parallel.
 9. The system of claim 1, where the inlet hose has a length to supply a hydraulic head pressure sufficient to have a flow of water over the impeller of at least three feet/second.
 10. The system of claim 1, where the inlet hose, the venturi chamber, the impeller and the exit hose are configured to maximize electricity produced by the generator.
 11. The system of claim 1, where the generator is between two and one hundred pounds.
 12. The system of claim 1, where the inlet hose is connectable to the generator inlet by means of a quick connect coupling.
 13. The system of claim 1, where the outlet hose is connectable to the generator inlet by means of a quick connect coupling.
 14. The system of claim 1, where the inlet hose further comprises a protective front portion configured to prevent marine life and debris from entering the inlet hose.
 15. The system of claim 14, where the inlet hose further comprises a mounting device to keep the protective front portion of the inlet hose just below the surface of the center of a stream where the maximum water velocity is located.
 16. The system of claim 1, where the outlet hose comprises a mounting device to place the outlet hose in a stream so as to not significantly affect streamflow, stream banks or otherwise cause un-natural erosion of an area around where the generator has been placed. 